Farm-grown Biofertilizers

Farmers around the world are creating their own low-cost, highly productive biofertilizers

This is an edited version of Steve Diver’s talk at the 2024 Acres U.S.A. Eco-Ag Conference. 

Farm-brewed biofertilizers, which function as both biostimulants and microbial inoculants, are an exciting topic. These eco-friendly tools are really empowering to farmers, and it’s a worldwide movement. 

When you hear people talking about the importance of “soil carbon,” it really boils down to soil organic matter and the living soil, which is achieved through biological farming practices. For ages, farmers have observed improvements to soil tilth from the use of compost and cover crops. A quick way to understand the agroecological basis of “organic farming” is to call it “organic matter farming,” or “carbon farming.” 

This is the heart of regenerative agriculture. It focuses on biological farming practices to build and maintain spongy soil organic matter and, more importantly, to gain all the benefits of soil organic matter functioning and its ability to unify the chemical, physical and biological soil components. This in turn leads to a rich soil habitat that supports soil-food-web functioning, or soil-microbial-community functioning. 

The plant microbiome is made up of microbial communities that inhabit and interact with the rhizosphere, the phyllosphere and the endosphere. The rhizosphere and the phyllosphere are those three-dimensional zones around the roots and leaves of plants. This is where biological farming practices can modify and enhance microbial abundance and diversity.

These microbial communities provide vast known and unknown “ecosystem services.” They fix nitrogen. They fix carbon. They transform nutrients like nitrogen, phosphorus and sulfur into plant-available forms. You’ve heard about phosphorus-solubilizing bacteria, but there’s also potassium-, manganese- and zinc-solubilizing bacteria. Beneficial microbes suppress diseases and insects. They produce phytohormones and a long list of bioactive substances and metabolites. They produce organic acids and enzymes, which are nature’s work horses. Finally, they produce polysaccharides — those biotic slimes and glues that bind soil particles together and build soil structure. 

Biostimulants, Biofertilizers and Biopreparations

Plant biostimulants are natural and biotic substances — including microorganisms — that are applied to seeds and plants to accelerate plant growth and to increase nutrient availability, crop yield, photosynthesis and hormonal activity. They also increase tolerance to drought, salinity and antibiotic stress. Biostimulants are applied in limited quantities yet have a powerful influence on plants separate from any nutritional or fertilizer effect. 

A few well-known biostimulants include those of geologic (humates, silicon), plant-based (algae, yeast, seaweed and alfalfa), biogenic (amino acids, organic acids enzymes), microbial (plant-growth-promoting rhizobacteria, polymicrobial strains of bacteria and fungi), protein hydrolysate (slaughter byproducts), and anaerobic digestate (plant and animal biogas slurries) origin. 

Soil biostimulants are natural and biotic substances that feed and stimulate soil microbial organisms to encourage their proliferation and functional activity. Many of these have dual slow-release fertilizer value, although they are usually applied in smaller quantities such as ounces, quarts or gallons per acre. Classic soil stimulants include fish hydrolysate, molasses, humates, seaweed, marine shells, ocean minerals, biodynamic preparations and silica. It’s popular to talk about foliar fertilization, but regenerative farmers know that soil biosprays and root-zone injections can jump start biological enrichment and nutrient cycling in the rhizosphere. 

Biofertilizers are biostimulants and slow-release organic fertilizers of microbial origin that promote plant growth. Composts and vermicomposts are old school biofertilizers — they promote plant growth through rich microbiology, slow-release fertility and biotic substances. Bokashi, or fermented organic matter, is a hot topic, and farmers are very inventive in creating dozens of bokashi recipes using local biomass resources. 

Then there is a long list of microbial inoculants that entail plant-growth-promoting rhizobacteria (PGPRs), plant-growth-promoting microorganisms (PGPMs), bacteria that solubilize phosphorus and minerals, and everything from single- to multiple-strains of key bacteria and mobilizing mycorrhizal fungi. Polymicrobial inoculants are appealing because they contain multiple genera and multiple species within a genus, producing more functional activity, more nitrogen fixation, more P-solubilization, etc.

Biopreparations include all of the above, plus related farm-made concoctions such as biofertilizers, bokashi, fermented plant extracts, bioferments such as LABs (lactic acid bacteria) and IMOs (indigenous microorganism ferments), mineral broths and chelates, and barrel-fermented liquid biofertilizers. Biopreparations more broadly aim for fertility, pest control and bio-stimulation. The emphasis is on low cost, on-farm biopreparations with selective purchased inputs. Brown sugar, molasses, wheat bran, rice, milk, rock phosphate and humates are some of the purchased inputs you’ll need to concoct biopreparations.

Cellular Activity

Understanding cellular activity and cellular mechanisms helps put all this into context.

Cells are like complex biofactories. They’re involved in the conversion of sunlight into carbon-based molecules by plants and microorganisms. Cells are responsible for the manufacture and decomposition of every life form that occurs in nature. The cytoplasm of plant cells can produce over 200,000 different carbon-based molecules. These cellular processes take place at warp speeds. There can be 60 million chemical reactions in a ribosome in a single minute, taking place in the micro-nanosphere — that’s one millionth to one billionth of a meter. 

Let’s look at bacterial and microalgal cells. They have the ability to convert carbon, hydrogen and oxygen — with the help of key minerals and trace elements — into millions of small molecules or metabolites. They can produce more than 1,000 different enzymes — either primary or secondary metabolites.

Primary metabolites are produced by microbial organisms to maintain their structure and their living functions. These include amino acids, proteins, nucleic acids, vitamins, organic acids, enzymes, polysaccharides and waxes. Secondary metabolites are produced by the organism in response to environmental cues and stresses. They include hormones, polyphenols, antibiotics, terpenes, antioxidants, extracellular polysaccharides and pigments. 

An important point is that plants and microbes — including symbiotic mycorrhizal fungi — have co-evolved over roughly 450 million years. These metabolites are how plants and microbes communicate with each other and stimulate each other. More importantly, these secondary microbial metabolites make up the A-to-Z plant bio-stimulants that naturally occur in nature. 

Microalgae play an essential role in terrestrial and marine ecologies, but in addition — much like bacteria — they produce an enormous number of biostimulatory metabolites. The microalgae chart groups these metabolites into phytohormones, signaling molecules, antioxidants and micronutrients, polyphenols, polysaccharides, and other macromolecules. These metabolites interact with plants and promote growth enhancement, tolerance to stress, induced disease resistance, nutrient mobilization and bioavailability, antioxidant scavenging, and more. 

Pulling all this together, the biological basis of regenerative agriculture can be boiled down to this: 

1. Build it and they will come. Use multi-species cover crops and related biological farming practices to create a rich soil habitat where soil-food-web organisms can flourish and perform their work.
   
2. Brew it and spread it. Take advantage of the biofertilizer toolbox to create bioferments that jumpstart soil microbial functioning in the rhizosphere and phyllosphere. These same bioferments can knock back odors and create healthy probiotic living quarters in livestock barns.

Five Alternative Farming Systems That Utilize Biopreparations

Health food store carry probiotics like kombucha and kefir. These fizzy drinks are made with sugar and tea, or sugar and fruit, along with a SCOBY — those alien-looking microbial blobs known as a “symbiotic culture of bacteria and yeast.” This is a good introduction to fermentation technology because the bacterial and yeast species used to make probiotic drinks for human health are the same species that drive agricultural bio-ferments like LABs and IMOs. Moreover, these fermentation microorganisms — like lactobacillus, saccharomyces and streptococcus — produce antioxidants, biostimulatory metabolites and disease-suppressive compounds.

Now let’s talk about five alternative farming systems that are empowering farmers on a worldwide basis. These systems teach how-to methods and offer a toolbox of biofertilizers and biopreparations that aim for both fertility and pest control. 

Kyusei Nature Farming and EM Technology

In the late 1980s and early 90s, an organic farming system from Japan called Kyusei Nature Farming started spreading globally, expanding farmers’ awareness of beneficial anaerobic fermentations. Nature Farming was founded by Mokichi Okada in the 1930s. A video coordinated by the Nature Farming International Research Foundation in Japan, titled Life in the Soil, was shown at practically every organic farming conference in those days, helping to usher in an awareness of the amazing “soil food web.” It featured high-resolution videography of plant roots intermingling with earthworms, micro- and macro-arthropods, soil microflora including bacteria and fungi, and three-dimensional soil humus. Its message was that soil tilth could be improved by mimicking natural ecosystems through the use of cover crops and organic mulches. 

Aside from advocating the Eastern philosophy of extolling working in concert with nature, the biggest practical outcome from this movement was EM, or Effective Microorganisms, developed by Dr. Teruo Higa at University of the Ryukyus in Okinawa.

EM starts with a mother culture inoculant that you can purchase, although ready-to-use versions are also available. Recipes below in this article describe how to “activate” EM to make a primary fermentation. Once you have cultured activated EM, there are a dozen ways to use this farm-brewed starter culture to transform local biomass into secondary fermentations, which include bokashi, fermented plant extract, fermented fish, and an herbal-vodka concoction called EM-5 that is great for pest control. Using food-grade equipment, you can even make antioxidant probiotics for human health and livestock drinking water. 

Korean Natural Farming

Korean Natural Farming, or KNF, was developed by Han-Kyu Cho in Korea. As a young man, Cho studied Nature Farming in Japan for three years and learned the vital importance of enzymes and microbes; the nutritive cycle theory, which emphasizes different nutritional needs at different stages of life; and natural poultry husbandry. After pioneering and teaching fermentation and extraction methods for several decades, Cho’s educational outreach started reaching global audiences with the publication of Korean Natural Farming: Indigenous Microorganisms and Vital Power of Crop / Livestock in 1997. 

KNF is unique because it teaches farmers how to culture indigenous microorganisms (IMO) by collecting microflora from cooked rice tucked into forest litter as a starter culture. KNF recipes include IMO-1 through IMO-5, fermented plant juice, fermented fruit juice, fish amino acid, LAB (lactic acid bacteria serum), oriental herbal nutrients and others. 

Korean Natural Farming methods are popular with growers in Hawaii, and the University of Hawaii at Manoa has published the most extensive set of bulletins and research reports on this topic in the United States.

JADAM Low-Cost Organic Farming

JADAM was developed by Youngsang Cho, the son of Han Kyu Cho, who grew up attending KNF workshops taught by his father and helping make hundreds of IMO cultures and recipes. After graduating with a degree in horticulture, Youngsang Cho began his farming career. Through experimentation, he developed a scaled-down version of Asian natural farming called “JADAM,” which translates to “people who like nature.” A prominent theme with JADAM is low-cost organic farming methods and recipes that are fast and easy to make. It’s like the punk rock version of classical KNF.

On-farm JADAM biopreparation recipes include JADAM wetting agent, JADAM microorganism solution, JADAM sulfur, JADAM liquid fertilizer, JADAM herbal solution, JADAM calcium phosphate and others. When I attended a JADAM workshop with Youngsang Cho, I was really impressed with the disease control he’s getting on vegetable crops in humid, warm-season growing conditions in South Korea. Youngsang Cho’s book, JADAM Organic Farming: The Way to Ultra-Low-Cost Agriculture, his web page, and his workshops are packaged as a tutorial on how-to methods farmers can grasp. JADAM has become popular with market farmers and cannabis growers in the United States.

Vedic Krish / ZBNF

Vedic Krishi and Zero Budget Natural Farming are the inspiration for the natural farming movement in India. Vedic Krishi is interesting because it draws on biopreparation recipes from Vedic literature that is over 2,500 years old. Until the mid-1900s, the population of India was totally engaged in an agrarian lifestyle. They viewed the stars at night and intimately lived with natural daily rhythms and cycles of the seasons These savvy farmers knew how to use local herbs and leaves, cow manure, cow urine, ghee, ashes, animal bedding and animal slaughter to make fermentation recipes and composts for soil fertility and pest control. Another term for Vedic Krishi is Indigenous Technical Knowledge (ITK). Vedic Krishi recipes include Panchagavya, Beejamrit, Jiwamrit, Amritpani, Sanjibani and others.

Zero Budget Natural Farming was developed by Subhash Palekar, a farmer in Maharashtra in central India. Much like Bill Mollison, the co-founder of permaculture, Palekar modeled ZBNF after observations of natural forest ecosystems. ZBNF employs a system of mulches, intercropping annual crops with fruiting trees, natural moisture capture, and selected Vedic Krishi biopreparations for seed treatments, microbial inoculants for soils and crops, and pest control. The state government of Andra Pradesh has adopted ZBNF, and more than 30 million Indian farmers practice it in India.

Masanobu Fukuoka, the famous natural farmer in Japan, toured India and was another driving force behind this modern movement. On one of my own agricultural trips to India I toured Bhaskar Save’s farm in Gujarat. Save was known as the “Ghandi of Natural Farming” for his innovations, which were inspired by Fukuoka.

Worldwide Peasant Farming

On a worldwide basis there are many innovative pioneers and farmers who’ve invented, modified or adapted biofertilizers. I like to refer to this umbrella of practices as Worldwide Peasant Farming. It’s like an alphabet soup of biopreparations and microbial-driven biofertilizers that includes biodynamic preparations, farm bokashi, barrel-fermented liquid biofertilizers, LABs, fermented forest litter and liquid organic fertilizers. 

Biodynamic farming is well known for its focus on soil humus and food quality and was regularly featured in early editions of Acres U.S.A. in the 1970s. The founder of biodynamics, Rudolf Steiner, observed peasant farmers as a young man when he lived in Lower Austria in the 1860s-70s. Modern science has examined the biodynamic preparations — first cultured by Rudolf Steiner and Ehrenfried Pfeiffer in the 1920s — and found they are loaded with indigenous microorganisms.

 Jairo Restrepo Rivera, a modern-day pied piper of on-farm biofertilizers, is a consultant from Columbia who has written several books on this topic, including A New ABC of Organic Agriculture. Jairo taught a workshop in Indiana that I attended, and the recipes and methods in his workshops and books provides a phenomenal toolbox for eco-agriculture. Hotbeds for biofertilizer production by worldwide peasant farmers include Indonesia, Malaysia, India, and Central and South America, with increasing adoption in the United States and Europe.

Review of Several Key Biopreparations

Here are some of the biofertilizers and biopreparations you should know about.

EM — Effective Microorganisms

EM, invented by Teruo Higa in Japan, is a versatile multi-purpose microbial inoculant that more farmers should have in their toolbox. EM can be used as a human probiotic, livestock probiotic, soil inoculant or crop inoculant. It can bioremediate odors around livestock and compost yards, and it can be used as a starter culture to drive secondary fermentations and to transform fish, food wastes, fresh leaves, manures and other raw biomass resources into bokashis and biofertilzers. Aside from mycorrhizae, there are more research papers on EM than any other microbial inoculant in the world, so there’s plenty to draw upon for ideas. 

EM is powerful because it’s a microbial consortia of lactic acid bacteria, phototrophic bacteria, and yeast, although it’s common to also see actinomycetes under a microscope. This leads to a shelf-stable, self-regenerating product because the waste of one microbial organism becomes food for another. 

Lactic acid bacteria are fermentation microbes that convert carbohydrates to organic acids. They control odors, produce antibiotics that suppress pathogenic organisms, and produce biostimulant metabolites including hormones, vitamins and amino acids. Photosynthetic bacteria convert light into carbon compounds and produce antioxidant compounds, making EM a potent bioremediation tool. Yeasts are single-celled fungi involved in fermentation but also have the ability to fix nitrogen and produce an abundance of biocontrol and plant-stimulatory metabolites. Actinomycetes produce antibiotics, decompose organic matter and help build soil structure. 

The two professional manufacturers of EM in the United States — TeraGanix and SCD Probiotics — supply mother culture. Activated EM, or AEM, is a fun process that farmers can easily do with some basic equipment. The classic EM recipe is 1:1:20, meaning 1 part mother culture, 1 part molasses, and 18 parts of water. Super AEM is juiced up with ancillary ingredients such as herbs, fruit juice concentrates, ocean minerals, and EM ceramic powder. A key concept is that a diversity of substrates promotes a diversity of secondary microbial metabolites.

You’ll need a propane burner, a stainless-steel pot and a thermometer. When the 18 parts of water have warmed to 110°F, turn off the heat and add the molasses. When the temperature drops to 100°F, add the EM mother culture and any ancillary ingredients. Pour this solution into a fermentation vessel; this can be a 20-liter fermentation keg or a 35-gallon poly drum. Larger-scale setups use 55-gallon barrels, 275-gallon totes and 1,000-gallon stainless-steel dairy tanks. Keep the lid sealed, using an air lock, and ferment anaerobically for two weeks. It’s very important to maintain a fermentation temperature around 95°F. Smaller setups can use a thermostat-controlled waterbed heater strapped around the vessel. The pH should drop to 3.5, and AEM should have a sweet smell. Activated EM will keep for months after brewing. 

The accompanying table shows dilution rates for application at strong, medium and weak rates for typical uses in agriculture. EM becomes very affordable when you consider that during activation you actually grow 20 volumes of microbes to every one part of mother culture, and then you dilute it further to match your end-use purposes. EM is scale-neutral; it can be brewed and adapted in small-scale to large-scale farm operations.

Bokashi

Bokashi, or fermented organic matter, has become synonymous here in the U.S. with kitchen food-scrap buckets, but it’s really a generic practice on a worldwide basis with much wider applications. 

Type-I bokashi is made from wheat bran that is moistened with activated EM and molasses in a 1:1:100 solution using tepid water, fermented in a five-gallon bucket for two weeks, then spread out to dry. I refer to this kind of dried, sweet-smelling wheat bran as “kitchen-bran bokashi” because it used to cover fruit and vegetable peelings scraps in kitchen food-scrap buckets. 

Type-II bokashi is what I call “ag-bran bokashi.” The process similarly starts with moistening wheat bran with activated EM and molasses at 1:1:100, but the recipe will include soil amendments like fish meal or feather meal, rock dust, biochar, and the like. Ag-bran bokashi is popular with “living soil” cannabis growers. In our university greenhouse, we’ve found excellent plant growth promotion of transplant seedlings and bedding plants by amending a commercial peat-lite potting mix with ag-bran bokashi at 3 to 5 percent by volume. 

These bucket-based bokashi methods can be viewed as modular biofertilizers. That is, if you use the same ingredients and follow the recipe and procedures, you can reliably reproduce good-quality bran bokashi that will perform its duties. Additionally, besides EM, you can use LABs, IMO-2, and other farm-made starter cultures to ferment these bran bokashis.

Farm bokashis, in contrast, are practiced more widely by peasant farmers. There are dozens of farm bokashi recipes that utilize locally available biomass resources. Typical ingredients include carbon feedstocks (manure, fresh leaves), carbohydrate feedstocks (rice bran, wheat bran), biochar, and related organic materials. These are blended and moistened with water and molasses either with or without starter cultures using EM, LAB, or LiFoFer liquid biofertilizers. Another way to use farm bokashi is in tarp-covered and fermented “quick compost” that is ready in three weeks. 

Korean Natural Farming

Korean Natural Farming emphasizes indigenous microorganisms over purchased mother cultures. IMO-1 is made by filling a shallow wooden box with cooked rice, covered with a sheet of paper and maybe a wire mesh screen to prevent wildlife theft, then tucking this under leafy mulch found under forest trees or bamboo. This encourages local soil microflora to grow onto the cooked rice. After five days, this moldy rice is harvested, mixed with an equal weight of brown sugar, and filled inside a clay crock or glass jar at two-thirds full. After another week it will partially liquify into a microbial starter called IMO-2, which can be diluted and used to activate KNF recipes or be used as a soil and foliar inoculant.

LAB is a prominent KNF recipe that has become widely adopted in peasant farming. It is made with rice rinse-water and milk. It is loaded with lactic acid bacteria, which provide multiple functional benefits as a microbial starter, plant protectant and soil biofertilizer. Super Blue LABs are made with the addition of spirulina and kelp. Here again, a diversity of substrates promotes a diversity of microbial metabolites; one of the key biostimulatory metabolites produced by microalgae — aka spirulina— is phycocyanin. 

Fermented Plant Extracts

Fermented plant extracts (FPE) are an age-old practice in ITK, organic, and biodynamic farming systems that have become a foundational extract in the nature farming and peasant farming movements. The basic approach is to chop up fresh leaves from local native plants and garden herbs — even local weeds and aquatic plants — and to load them into a bucket or barrel about halfway to three-quarters full. The vessel is then topped off with water. Some farmers leave it open, and some seal the lid and let it get stinky without any starter cultures. Other farmers add microbial starters — such as molasses with EM, LAB or LiFoFer — and let it sweetly ferment with a sealed lid and air lock. There are differing viewpoints on fermentative anaerobic versus putrefactive anaerobic environments, but the key point is that farmers have the know-how to manufacture and use these bioferments. 

These fermented plant extracts are easy to make and possess a synergistic blend of soluble nutrients, plant-extracted phytochemicals and bioactive substances, and living microbiology and their secondary metabolites. A study from Zimbabwe looked at the nutrient content of FPEs made from water hyacinth, pigweed and comfrey. They found NPK analysis on par with many of the liquid organic fertilizers used in organic production, which contain soluble nitrogen in the 2 to 4 percent range.

Fermented Forest Litter (LiFoFer)

Fermented forest litter — Litières Forestières Fermentées — is very popular in France and is widely practice by worldwide peasant farmers. LiFoFer starts with collecting decaying forest litter from deciduous trees. This forest litter is mixed with wheat bran or rice bran, whey, and some water and molasses. This moist organic blend is packed into a 35-gallon barrel, using a sealed lid with an air lock, and allowed to ferment for 30 days. This transformed organic substrate is like a barrel-fermented bokashi that serves as a microbial starter. LiFoFer is also known as Mountain Microbes.

Barrel-Fermented Liquid Biofertilizers

Jairo Restrepo Rivera has popularized barrel-fermented liquid biofertilizers (BFLF), which are very much like biogas digesters, only the desired byproduct is the liquid biodigestate, or bio-slurry, which has NPK value. Production of BFLF requires a 35- or 55-gallon poly drum equipped with a locking lid. Basic ingredients loaded into this barrel include water, molasses, fresh cow dung, whey or yeast, and wood ashes. Cow rumen is a substitute for cow dung. This is fermented anaerobically with an air lock for 30 to 90 days. 

A fruit grower in Brazil, Delvino Magro, amended BFLF with minerals and trace elements in order to make chelated minerals, which are more readily absorbed through foliar feeding. His work was influenced by the Trophobiosis Theory of Francis Chaboussou, which aims for a metabolic approach to pest control using mineral nutrition. The “Super Magro” versions of BFLF include rock phosphate, rock dust and trace element salts of iron sulfate, manganese sulfate, boron, copper sulfate, zinc sulfate, etc. — intended for use as single- or multi-element chelates — amended with specific weight-per-volume measurements. 

Eco-Enzyme

Eco-enzyme, also known as garbage enzyme, was developed in the 1980s by Dr. Rosukon Poompanvong, founder of the Thai Organic Farming Association. It has been widely adopted in Thailand, Indonesia, Malaysia and India. This concoction is very simple to make. In a plastic jug, add 10 parts water, three parts of fruit and vegetable peelings, and one part molasses or brown sugar. After fermentation for three months, the pH will drop to roughly 3.5, and it will be loaded with acetic and lactic bacteria, fermentative fungi and potent enzymes. It can be used as an anti-microbial disinfectant, compost starter and liquid organic fertilizer.

Yeast

One of the simplest biofertilizers is dried yeast — simple store-bought baker’s yeast. Mix 30 grams of yeast and 30 grams of sugar in one liter of water and allow it to activate for a few hours. Then it’s ready for use as a soil drench or foliar spray. I’ve seen research reports that found a 30 percent increase in plant biomass from this kind of simple yeast biofertilizer. If this seems incredulous, just remember that every single-celled yeast is like a complex biofactory that naturally produces plant-stimulatory and crop-protectant metabolites.

Application of Biopreparations

One of my favorite concepts is MEND — Microbially Enhanced Nutrient Delivery — which was developed by Graeme Sait, an eco-ag consultant in Australia. 

The MEND theory says that the higher the density and diversity of microorganisms living in the rhizosphere and phyllosphere, the greater the assimilation and bioavailability of nutrients. This points to the importance of both carbon farming, with its rich soil habitat, as well as microbe-mineral liquid blends used in foliar feeding, fertigation and root injections while drilling seed. Regenerative farmers embracing these practices have found they can reduce fertilizer inputs by 25 to 75 — or even 100 — percent.

Biofertilizers, plant extracts, and bioferments fit completely with the MEND concept. Farmers should keep biosphere points of influence in mind. The three places where application of microbial blends can influence plant health include the seed zone, the root zone and the foliar zone. 

Steve Diver is the farm superintendent of the Horticulture Research Farm at the University of Kentucky. He was the winner of the 2024 Acres U.S.A. Eco-Farmer Achievement Award.